The Bureau of Land Management today announced its tentative fall-winter schedule for gathering wild horses and burros from overpopulated herds on drought-stricken Western public rangelands. The gathers and removals are needed to bring herd sizes into balance with other rangeland resources and uses, as required by Federal law. Changes to this gather schedule may occur if range conditions deteriorate more quickly than expected in certain Herd Management Areas (HMAs).

Sixty-five of the BLM’s 179 HMAs have already been identified as areas of concern because of drought and wildfire. Along with removals, the fall-winter gathers will be used to apply fertility-control vaccines during November through February, the ideal time for maximum efficacy. From October 1, 2012, to February 28, 2013, the BLM plans to remove approximately 3,500 wild horses and burros and apply fertility-control treatment to more than 900 others that will be returned to the range.

Additional summer gathers will be conducted starting in July 2013, with the specific number of removals and fertility-control applications yet to be determined. Population growth-suppression techniques will include applying porcine zona pellucida (PZP)-based fertility-control vaccines; adjusting sex ratios in some herds to favor males; and possibly applying other measures, all of which would be aimed at reducing the number of on-the-range pregnancies.

The public and media are invited to observe gathers conducted by helicopter. Observation points will be determined by the BLM in a manner that recognizes the need for good viewing sites, along with the need to ensure human and animal safety. Several gathers may use bait- and water-trapping methods, rather than helicopters, to capture the animals. Public and media observation of these passive types of gathers is unlikely to be permitted because of the inherent challenges involved in capturing the animals using these methods, such as the animals’ natural wariness.

All wild horse and burro gathers in the current fall-winter schedule will be completed by February 28, 2013. The tentative fall-winter gather schedule can be accessed at

The BLM estimates that approximately 37,300 wild horses and burros (about 31,500 horses and 5,800 burros) are roaming on BLM-managed rangelands in 10 Western states based on the latest data available, compiled as of February 29, 2012. Wild horses and burros have virtually no natural predators and their herd sizes can double about every four years. As a result, the agency must remove thousands of animals from the range each year to protect rangeland resources, such as wildlife habitat, from the impacts of overpopulation. The 1971 Wild Free-Roaming Horses and Burros Act mandates that once the Interior Secretary “determines...that an overpopulation exists on a given area of the public lands…he shall immediately remove excess animals from the range so as to achieve appropriate management levels.”

The BLM manages more than 245 million acres of public land, the most of any Federal agency. This land, known as the National System of Public Lands, is primarily located in 12 Western states, including Alaska. The BLM also administers 700 million acres of sub-surface mineral estate throughout the nation. The BLM's mission is to sustain the health, diversity, and productivity of Americas public lands for the use and enjoyment of present and future generations. In Fiscal Year 2015, the BLM generated $4.1 billion in receipts from activities occurring on public lands.